BoingBoing runs a terrific photo of chimps watching a dead chimp being transported, and asks anyone to deny that the chimps are grieving.

On the one hand, I don’t doubt for a moment that animals feel emotions. (Neither did Darwin, by the way. He seems to have been quite connected to his dogs.) Nor do I doubt that the chimps are grieving. I just don’t think the photo is evidence of grief; someone who doesn’t think animals feel social emotions wouldn’t be swayed by it. It just shows that chimps can pay attention.

Of course, the more important point to me isn’t whether what chimps feel when a member of their group dies is grief or should be called something else. It isn’t even whether animals feel what we call emotions (although I’m sure they do). The point is that animals other than humans care about themselves, their world, and sometimes others. The caring can be so primitive that at one end of the spectrum it’s not worth arguing for, but pretty far down the stack I’m convinced that to deny that animals care about what happens to them â€” and, eventually, what happens to their significant others â€” is just perverse. That caring is what we feel as emotions. The fact of that caring is the fundamental reason I’m a vegetarian.

But, that’s not what I wanted to ask. The comments to the BoingBoing post are quite funny. Along the way someone points out that 98% of our DNA is the same as the chimp’s. Which always makes me want to ask: How much of our DNA do we share with animals not nearly as obviously like us? With whales? With flounders? With brine shrimp? How much difference is in that top 10% of shared DNA?